Punch attaching construction



Jan. 12, 1960 FIG; 2 0

F. w. ANTILA 2,920,913

PUNCH ATTACHING CONSTRUCTION Filed Sept. 12. 1958 FIG.3

I2 g I am 234 IL J I33 I35 22 I31 I34 23I E G 228' INVENTOR FRANK W. ANTILA ATTORNEYSv United States Patent PUNCH ATTACHlNG CONSTRUCTION Frank W. Antila, Minneapolis, Minn., assignor to ONeil- Irwin Manufacturing Company, Lake City, Minn., a

The herein disclosed invention relates to punch attaching construction for attaching punches to the mounting of a die set and has for an object to provide an attaching construction by means of which the punchv may be accurately located at a predetermined location.

Another object of the invention resides in providing a punch attaching construction in which the entire construction is confined to an extremely small and limited space on the surface of the mounting so as to permit of the attachment of numerous punches in close proximity to one another.

A still further object of the invention resides in providing a punch attaching construction in which the punch may be attached to the mounting by means of a single screw or similar attaching member.

A feature of the invention resides in providing means serving as a dowel for holding the punch from lateral movement and in providing a construction in which the dowel and screw are concentric.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings:

Fig. 1 is an elevational-sectional view of a portion of a mounting of a die set together with a punch and punch holder mounted thereon and illustrating an embodiment of the invention.

Fig. 2 is an inverted view of the structure shown in Fig. 1.

Fig. 3 is a view similar to Fig. 1 of the parts separated from one another.

Fig. 4 is a view similar to Fig. 1 of a form of the invention in which a non-circular punch is employed.

Fig. 5 is a view similar to Fig. 2 of the structure shown in Fig. 4.

Fig. 6 is a view of the punch shown in Fig. 5 and detached from the holder.

Fig. 7 is a view similar to Fig. 1 of a modification of the invention.

The invention utilizes a die set 10, a portiononly of which has been shown in the drawings. This portion of the die set consists of a mounting 11 which is plate-like in form and which has a downwardly facing face 12 and an upwardly facing face 13. The die set being of a construction well known in the art, has not been shown in detail in the application though it may be readily comprehended that any similar construction to that now well known in the art may be employed.

The punch of the invention is shown in detail in Figs. 1 and 3 and is designated by the reference numeral 14. This punch comprises a shank 15, cylindrical in form, and from which issues a reduced portion 16 forming the punch proper. The punch proper as illustrated is designed to punch a circular hole and cooperates with a suitable die in the customary manner. The shank 15 is drilled to form a bore 18 and is internally threaded to provide threads 19 in said bore. The shank 15, the bore 1!} and the punch proper 16 are all coaxial.

Patented Jan. 12, 1960 Cooperating with the shank 15 of the punch 14 is a punch holder 20 which is formed with a body 21. At one end 28 of this body is a cylindrical boss 22 having a free end 27. At the opposite end 24 of the body 21, the same is formed with a cylindrical socket 23 opening through the said end of said body. This socket and the boss 22 are coaxial. In the drawing, a cylindrical body 21 has been illustrated which is of greater diameter than the boss 22 thereby forming a shoulder 25 normal to the axis of the socket 23. The punch holder 21 is also constructed with a cylindrical hole 26 which extends through the end 27 of the boss 22 and communicates with the socket 23. This hole is also coaxial with respect to said socket and boss.

For attachment of the holder 22 to the mounting 11, a cylindrical cavity 31 is formed in the mounting 11 and which extends through the face 12 of said mounting. The axis of this cavity is normal to the face 12 and is of such dimensions as to snugly receive the boss 22-. The depth of the cavity 31 is greater than the length of the boss 22 so that when the boss is inserted into said cavity the shoulder 25 comes into engagement with the face 12 of the mounting. The mounting 11 is formed with a hole 32 similar to the hole 26 in the holder 20 and coaxial with reference thereto. At the end of this hole is also formed a counterbore 33 also coaxial with reference to said hole and which extends through the face 13 thereof. For securing the parts in position, a screw 34 is employed which has a threaded shank 35 screwed into the threads 19 of punch 14. The said screw is further formed with a head 36 which is received in the counterbore 33 and which engages the surface 37 of the mounting 11 at the end of said counterbore. When the parts are assembled as shown in Fig. 1 and the screw 34 tightened, the parts are drawn together and the single screw 34 serves to attach all of the parts in position.

In the mounting of the punch, the location for the center of the punch is accurately determined on the face 12 of the mounting 11 and said mounting bored to form the cavity 31. Concurrently therewith the said mounting is drilled to form the hole 32 and subsequently counterbored from the opposite side to form the counterbore 33. The parts are then assembled and the screw 34 applied to attach the parts to the mounting. The screw 34 together with the cooperating parts of the punch, holder and mounting constitute attaching means which draws the punch into the socket in the holder and the holder into the cavity in the mounting and maintains the parts securely assembled.

In Fig. 4, a modification of the invention is disclosed in which a punch having an ovular shaped punch proper is illustrated. Due to the similarity of the parts, the corresponding parts will be designated by the same reference numerals preceded by the digit 1 and the description thereof will not be repeated. In this form of the invention, the o-vular punch proper is indicated by the reference numeral 140, With this form of the invention it becomes desirable to prevent the punch 14 from rotating relative to the holder 21). For the purpose the shank is constructed with a flat 141 extending partially along one portion thereof and longitudinally with respect thereto. The adjoining portion 142 of the punch holder 20 at the end 24 thereof is swedged over the fiat 141 by means of a sharp tool such as a cold chisel which is driven into the said end in a manner to force the metal of the holder against said flat. The device is then mounted as previously described.

In Fig. 7 still another form of the invention is shown. Due to the similarity of the parts the corresponding parts will be given the same reference numerals used in the description of the form shown in Figs. 1 and 2, with the digit 2 preceding the same, and the description thereof will not be repeated. In this form of the invention the hole 226 in the holder 220 is made slightly smaller and tapped as indicated at 243 to receive the threaded shank 235 of the screw 234. This holds the holder 220 secured to the mounting 211. The punch is held in position in the socket 223 by means of a set screw 244 which is screwed into atransverse threaded hole 245 in the body 221 of the holder 221?. This set screw engages a conical depression 245 in the shank 215 of the punch to hold the punch securely mounted in the punch holder.

The advantages of the invention are manifest. Punches can be accurately located by accurate layout Work on the mounting and the mounting bored ina lathe or drill press to correspond with the marking. All of the holes required for the mounting of the punch are concentric so that considerable time is saved in the machining of the mounting for the punch. By means of the invention, minimum space is required in attaching the punch so that punches may be closely positioned and individually attached without interference. In one form of the invention a single screw may be used to secure all of the parts in position.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. In a punch attaching construction having a punch provided with a cylindrical shank, a punch holder having a socket receiving said shank said socket having an end surface against which the end of the shank bears, a cylindrical boss on said punch holder, an outwardly extending annular planiform shoulder on said punch holder encircling said boss and normal to the axis thereof and facing in a direction away from said socket, a mounting having a planiform face and a cylindrical cavity therein extending through said face with the axis of said cavity normal to said face, said boss being received in said cavity and said shoulder engaging said face, the combination of threads in said shank coaxial with reference thereto, said punch holder having a cylindrical hole therein concentric with and communicating with said socket, said mounting having a cylindrical hole coaxial with reference to the hole in said punch holder and extending completely through the same and communicating with said cavity, and a screw extending through said holes and screwed into the threads in said shank and drawing the end of said shank toward the end surface of the socket and said shoulder toward said face,

2. In a punch attaching construction having a punch provided with a shank, a punch holder having a socket therein receiving said shank, a boss formed on said punch holder, a shoulder on said punch holder encircling said boss, a mounting having a face and a cavity therein extending through said face and receiving said boss, the combination of a single attaching member engaging said shank and said mounting and urging the end of said shank against the, end of said socket and urging said shoulder against said face.

References Cited in the file of this patent UNITED STATES PATENTS 59,823 Crate Nov. 20, 1866 483,095 Barrow Sept. 20, 1892 1,322,525 Bowers Nov. 25, 1919 

